40 HYMENOPTERA OF AMERICA. [PART I. 



29. Z. Montezuma Sauss. (Fig. 3, 3a.) — Parvulas, rugosus, niger 

 et pilosus; abdomine ovato ut in genere Eumene; petiolo elongato 

 penngoso; reliqua parte abdominis piril'ormi, depressa ; pronoti, post- 

 scutelli et abdominis segmentorum 1, 2, margine, flavo vel ferrugineo; 

 scapo, macula subalari et scutelli, margineque clypei, navis. 



Zethus Montezuma Sactss. Revue Zool. IX, 1857, 270. 

 Z. Guatemotzin Sadss. ibid. (var. 9 )• 



9. Total length, 13 mm. ; wing, 10 mm. 



% . Total leugtb, 10 mm. ; wing, 8 mm. 



9. Insect small, slender; bead but little inflated. Ocelli in a 

 regular or even lengthened triangle. All the head rugose, crib- 

 rose with coarse punctures; clypeus entire, also cribrose, convex 

 and rugose. Thorax lengthened, one and a half times longer than 

 wide, cribrose with large punctures, rugose ; on the disk of the 

 mesothorax two arcuate grooves leave the scutellum, and extend 

 to the anterior suture. Angles of the prothorax spinose ; its 

 margin relatively little prominent. Metathorax attenuated, con- 

 vex, rugose, but with a lateral, very distinct truncation. Petiole 

 quite lengthened, its anterior third, at least, linear; the remainder 

 enlarged, pyriform, much lengthened and truncate, rugose, cribrose 

 with very large punctures (larger than those of the thorax) ; its en- 

 largement but little raised, hardly contracted behind, its marginal 

 depressions forming a transverse groove. The remainder of the 

 abdomen depressed, regularly pyriform, lengthened as in the 

 Eumenes, at the base sub-pediculate, gradually swelling; the 

 second segment shining, polished, silky -gray, delicately punctured, 

 more coarsely along its border. 



Insect black, very hairy, even its abdomen being covered with 

 a pile of erect hair in fresh specimens; hair of the head and 

 thorax obscure ; that of the metathorax and of the abdomen gray. 

 Inferior and lateral border of the clypeus often ferruginous ; a 

 line under the scape of the antenna?, two dots at their insertion, 

 margin of the prothorax, a point under each wing, two at the 

 scutellum, two on post-scutel, and the border of the first two 

 abdominal segments yellow or ferruginous. These markings are 

 variable, the scutellum being often black and the post-scutel yel- 

 low ; or the markings are entirely wanting. Wing-scales brown 

 or ferruginous. Wings hyaline, nervures brown, and often a 

 brown cloud in the radial cell. 



%. Smaller. Clypeus transverse, black, covered with silky. 



